The following relates generally to memory devices and more specifically to boosting a voltage of a digit line during a write operation to a ferroelectric memory cell.
Memory devices are widely used to store information in various electronic devices such as computers, wireless communication devices, cameras, digital displays, and the like. Information is stored by programming different states of a memory device. For example, binary devices have two states, often denoted by a logic “1” or a logic “0.” In other systems, more than two states may be stored. To access the stored information, the electronic device may read, or sense, the stored state in the memory device. To store information, the electronic device may write, or program, the state in the memory device.
Various types of memory devices exist, including random access memory (RAM), read only memory (ROM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), ferroelectric RAM (FeRAM), magnetic RAM (MRAM), resistive RAM (RRAM), flash memory, and others. Memory devices may be volatile or non-volatile. Non-volatile memory (e.g., flash memory) can store data for extended periods of time even in the absence of an external power source. Volatile memory devices (e.g., DRAM) may lose their stored state over time unless they are periodically refreshed by an external power source. A binary memory device may, for example, include a charged or discharged capacitor. A charged capacitor may, however, become discharged over time through leakage currents, resulting in the loss of the stored information. Certain features of volatile memory may offer performance advantages, such as faster read or write speeds, while features of non-volatile memory, such as the ability to store data without periodic refreshing, may be advantageous.
In some architectures, to write a logic state to an FeRAM memory cell, a positive voltage or a negative voltage is applied across a ferroelectric capacitor of the FeRAM memory cell. Once the voltage is removed, the ferroelectric capacitor may remain polarized—e.g., it may retain one of two charge states corresponding to a logic state “0” or a logic state “1”—based on the voltage applied across the ferroelectric capacitor. In some cases, the amount of charge stored by ferroelectric capacitor for a particular logic state is dependent on the magnitude of the voltage applied across the ferroelectric capacitor, and variations in stored charge may affect the accuracy of a subsequent read operation.